The present invention generally relates to a picture display apparatus, and particularly relates to an apparatus which is to be connected to a testing device having a purpose of displaying the result of test as a picture, for example, a measurement device of low resolution such as an ultrasonic inspector, a radiation computerized tomography, a radar pickup device, etc., so as to display a picture with high resolution.
As disclosed in the publication of JP-A-No.-50-137184, the conventional picture display apparatus could be applied only to a testing or measurement device capable of approximating the spatial resolution with a Gaussian distribution, and inverse Weierstrass transformation was applied to a measured spectrum so as to derive a spectrum improved in resolution. Accordingly, the conventional picture display apparatus could not be used for a measurement device having a spatial resolution having a distribution which is unknown or which is different from a Gaussian distribution.
The above-mentioned conventional picture display apparatus could be applied only in the case where the spatial resolution of the measurement device used was known or had a Gaussian distribution. Accordingly, it was required to obtain the spatial resolution of the measurement device in advance by any other means. In order to satisfy this requirement, a picture display apparatus has been proposed in which the resolution peculiar to the measurement device is calculated on the basis of a spectrum representing an object having a known shape and a measured spectrum of the same object, so that the measured spectrum deteriorated on account of the low resolution of the measurement device is automatically converted into a spectrum of high resolution so as to make it possible to display a clear and detailed picture. In this picture display apparatus, however, there has been such a problem that measurement errors or the like contained in the measured spectrum may make the values of the measured spectrum large in a high frequency range to produce high frequency oscillations in a picture displayed to thereby make the picture unclear. This apparatus is disclosed in Japanese Patent Application No. 60-115136 filed in the name of the same assignee on July 16, 1985 and laid-open on Jan. 26, 1987 under Laid-Open No. 62-017654.